Engine starter gearing



Feb. 21, 1961 E. E. HOOD ENGINE STARTER GEARING Filed Oct. 12, 1959 INVENTOR.

2,972,257 Patented Feb. 21,1961

ENGINE STARTER GEARIN G Edwin Elliott Hood, Elmira, N.Y., assignor to The Bendix Corporation, a corporation of Delaware Filed Oct. 12, 1959, Ser. No. 845,816

Claims. (Cl. 749) The present invention relates to engine starter gearing and more particularly to starter gearing of the automatically engaging and disengaging type which is operable by a reversible motor to crank an engine in either direction of rotation.

The increasing popularity of two-cycle engines with high power ratings for outboard marine use has created a demand for electrical starters for such units. Moreover, it has been found both desirable and practical to maneuver water craft powered by two-cycle engines by reversing the engines rather than by employing reverse gearing for that purpose. This, of course, entails a reversible engine starter gearing.

It is an object of the present invention to provide a novel reversible engine starter gearing which is eflicient and reliable in operation and simple and economical in construction.

it is another object to provide such a device which is adaptable to a reversible starting motor and which is arranged to engage and rotate an engine gear responsive to acceleration of the starting motor in either direction of rotation; and which disengages from the engine gear when the engine becomes self-operative.

It is another object to provide such a device incorporating a unitary yielding means for cushioning the shock of initial engagement in either direction of rotation.

it is another object to provide such a device incorporating means fordemeshing and preventing rebounding of the drive pinion into engagement with the engine gear after being demeshed when the engine starts, and for preventing the pinion from drifting into mesh with the engine gear during operation of the engine.

Further objects and advantages will be apparent from the following description taken in connection with the accompanying drawing in which:

Fig. 1 is a side elevation, partly broken away and in section, of a preferred embodiment of the invention; and

Fig. 2 is an exploded detail in perspective of the driving member, the driving cam sleeve, and the pinion with its driven cam member.

In Fig. 1 of the drawing there is illustrated a powler shaft 1 which may be the extended armature shaft of a starting motor (not illustrated). The shaft 1 is reduced in diameter as shown at 2, providing a radial shoulder 3 and is formed with axially extending spline grooves 4.

A driving member 5 having internal splines 6 cooperating with the spline grooves 4 is slidably but non-rotatably mounted on the reduced portion 2 of the driving shaft and is counterbored for the reception of a hollow cylindrical cushioning member 7 of elastically deformable material such as rubber. A bearing annulus and thrust member 8 is seated against the shoulder 3 on the armature shaft and has a sliding bearing in the interior surface of the counterbored portion of the driving member 5. It thusslidably supports the open end of the driving member and cooperates with the cushioning member 7 to form a yielding abutment means limiting the movement of the driving member to the left in Fig. 1.

A pinion 9 is slidably journalled on the extended portion 2 of the power shaft 1 for movement into and out of mesh with an engine gear 11, a bearing sleeve 12 being preferably interposed to rotatably support the pinion on the power shaft.

A tubular sleeve member 13 (Fig. 2) is keyed on the cylindrical exterior bearing surface of the driving member 5 as by means of keying projections 14 on the driving member entering complementing notches 15 in one of said sleeve. Sleeve 13 is provided with a pair of symmetrical axial cam lobes 16, 1'7 extending from the other end and overlying the bearing surface of the driving member 5. A cup-shaped cam member 18 fixed on the pinion 9 in any suitable manner as indicated at 19 is also arranged to rotatably and slidably bear on the exterior bearing surface of the driving member 5 and has cam lobes 21, 22 mating with the cam lobes 16, 17 of the sleeve 13. Relative rotation of the pinion in either direction with respect to the driving member 5 will thus cause the pinion to be moved from its idle position toward meshing engagement with the engine gear 11.

Means for limiting the meshing movement of the pinion and defining its operative position is provided comprising a thrust sleeve 23 slidably mounted on the bearing sleeve 12 on the motor shaft and interposed between the pinion 9 and a thrust ring 24- also slidably mounted on the sleeve 12. A cooperating thrust ring 25 is fixedly mounted on a final reduced extension 26 of the motor shaft 1 as by means of a stop ring 27 retained by a nut 28 threaded on the motor shaft.

The thrust rings 24, 25 are counterbored as shown at 29, 31 for the reception of a compression spring 32 which normally maintains the pinion 9 in idle position and promptly returns it to such position as soon as the cranking load is relieved by the self-operation of the engine. The counterbores 29, 31 are sutficiently deep to house the spring 32 and allow the thrust rings 24, 25 to come into direct contact during the cranking operation and thereby positively limit the travel of the pinion.

In operation starting with the parts in the positions illustrated in Fig. 1, acceleration of the driving shaft 1 by the starting motor in either direction of rotation, transmitted through the driving member 5 to the cam sleeve 13, causes the latter to move the pinion 9 into mesh with the engine gear 11 by the co-action of the cam lobes 16, 17 and 21, 22 of said members. The axial movement of the pinion towards the meshed position urges the sleeve 23 against the thrust ring 24 and the latter into engagement with the fixed thrust ring 25 so as to define the extent of axial movement. The pinion 9' is then compelled to rotate with the driving shaft 1 to thereby rotate the engine gear 11 and crank the engine. The shock of initial acceleration of the cranking load is cushioned by backward movement of the driving member 5 against the yielding abutment provided by the cushioning sleeve 7 and the annulus 8.

When the engine starts, the release of the cranking load permits the spring 32 to move the pinion 9 back to the idle position, where it is maintained until subsequent actuation of the driving shaft.

The height of the earns 16, 17 and 21, 22 is sufliciently greater than the travel of the pinion from idle position to cranking position, to provide for adequate compression of the elastic sleeve to transmit the cranking torque. In cases where it is desired to limit the cranking torque to a predetermined maximum, the cams are so formed as to slip past each other when that torque is exceeded.

Although but one form of the invention has been shown and described in detail, it will be understood that changes may be made in the precise form and arrangement of the parts without departing from the spirit of the invention.

I claim:

1. In a reversible engine starter drive a power shaft, a driving member splined to'said shaft providing an axial bearing surface, a pinion slidably journalled on the power shaft for movement into and out of mesh with a gear of an engine to be started, a substantially tubular sleeve member keyed at one end thereof to the driving member having a plurality of symmetrical axial cam lobes extending from the other end and supported on said bearing surface, a substantially cup shaped cam member fixed on the pinion having axially extending cam lobes rotatably and slidably supported on said bearing surface mating with those of said sleeve member, yielding means urging the pinion away from the engine gear, a yielding abutment means limiting movement of the driving member away from the engine gear, and stop means for defining the meshing position of the pinion on the power shaft.

2. A reversible engine starter drive as set forth in claim 1 in which said driving member is counterbored to slid- .ably enclose said abutment means, and said abutment means includes a bearing annulus slidably supporting the open end of the driving member.

3. A reversible engine starter drive as set forth in claim 1 in which the means for defining the meshing position of the pinion comprises a thrust sleeve slidably mounted on the power shaft engaging said pinion, a pair of thrust rings on said shaft in the path of movement of the thrust V 4 sleeve, and a stop ring fixed on the power shaft confining said thrust rings and thrust sleeve on the shaft.

4. A reversible engine starter drive as set forth in claim 3 in which said means for urging the pinion away from the engine gear includes a compression spring interposed between the thrust rings and thereby normally retaining the pinion in a demeshed position.

5. In a reversible engine starter drive a reversible rotatable power shaft providing a bearing surface, a drive member splined on the shaft, a pinion slidably journalled on the shaft for movement into and out of mesh with a gear of an engine to be started, a first cam member fixed on the drive member having an axially extending lobe in overlying supported relation to said bearing surface, a second cam member fixed on the pinion formed with an axially extending lobe rotatably and slidably supported on said bearing surface cooperating with the lobe of said first cam member, yielding means urging said cam mem here into cooperation, and stop means defining the meshing position of the pinion on the shaft.

References Cited in the file of this patent UNITED STATES PATENTS UNITED STATES- PATENT. meme 4 TEFEQAE G QQR'GTEN Patent N06 2 -9'Z2 257 February 21,, 1961 Edwin Elliott Heed It is hereby certified that error appears in the abev'e numbered pat ent requiring correction and that the said Letters Patent should read as corrected below Column 2 line 9 after "one" insert end line 46 for "Qffl, first oeetmrenee read on celumn 4 line 9, strike out providing a bearing surface" and insert the same after "shaft" and before the comma in line 1C same column 41.,

Signed and sealed this 9th day cf January 1962 (SEAL) Attest:

ERNEST W, SWIDER AVE L. LD

Attesting Officer Commissioner of Patents UNITED STATES- PATENT. @FFECE 4 eemimewe oi eoeeeefiem Patient Noe 2 -972 257 February 21 1961 v Edwin Elliott Heed It is hereby certified "that error appears in the above numbered pat ent requiring correction and that the said Letters Patent should read as corrected below Column 2 line 9 after "one" insert end line 46 for "offl, first oeem menee read on column 4 line 9, strike out providing a bearing surface" and insert the same after "shaft" and before the comma in line 1C same column 41.,

Signed and sealed this 9th day of January 1962 (SEAL) Attest:

ERNEST W SWIDER DAVID L. LADD Attesting Officer Commissioner of Patents UNITED STATES PATENT. eFFICE QTIFICAE o QC'H Patent Nos 2 -972 25'z February 21,, 1961 Edwin Elliott Heed It is hereby certified that error appears in the above numbered pat ent requiring correction and that the said Letters Patent should read as corrected below,

Column 2 line 9 after "one" insert end line 46 for "of"., first occulmeenee read on column 4 line 9, strike out "providing a bearing surface" and insert, the same after "shaft" and before the comma in line 10* same column 41.

Signed and sealed this 9th day of January 1962w (SEAL) Attest:

ERNEST W: SWIDER DAVID L, LADD Attesting Q fi l' Commissioner of Patents 

